The storage of electronic data is one of the most important aspects of business and every day life. Therefore, increasing performance in data access and storage may have profound effects. One method utilized to provide persistent and reliable data storage is through the use of a RAID array. The basic idea of RAID is to combine multiple data storage devices into a group which yields performance exceeding that of one large, more expensive device. This array of small drives is made to appear to a computer or over a network as a single virtual drive. In addition, the array can be made fault-tolerant by redundantly storing information in various ways, such as through employing different RAID types.
To help users avoid data loss, some drive manufacturers are now incorporating logic into their drives that act as an “early warning system” or “predictive failure” for pending drive problems. This system is called Self-Monitoring Analysis and Reporting Technology or SMART. The hard disk's integrated controller monitors various aspects of its own performance and makes available status information to any software that wants to probe the drive and examine the data. Typically, SMART works by monitoring certain performance characteristics inside the disk, and looking for trends that indicate a gradual worsening in reliability that may indicate an imminent failure.
However, in the case of systems with redundant storage, system administrators have either ignored the SMART indication and waited for the drive to fail or replaced the drive before it failed, and rebuilt the drive from other redundant storage. However, in utilizing this method, the rebuild for the drive would fail if the other drive from which rebuild was performed includes media errors or the rebuild would continue including the errors. Moreover, if one of the drives from which rebuild was taking place failed, the entirety of the logical drive would fail.
Therefore, it would be desirable to provide a system and method for increased availability.